Draft control apparatus for furnaces



Aug. 8, 1933. R, MaCD 1,921,763

DRAFT CONTROL APPARATUS FOR FURNACES Original Filed Sept. 10, 1928 2. Sheets-Sheet l ml L666: 77MB? Aug. 8, 1933. acD u A 1,921,763

DRAFT CONTROL APPARATUS FOR FIJI WAGES Original Filed Sept. 10, 1928 2 Sheets-Sheet 2 ,wLiu/e Patented Aug. 8 1933 UNITED? STATES TENT'QFFEE 4 7 DRAFT CONTROL APPARATUS FOR f V FURNACES 7 Robert MacDougall, Granite City, 111. assignor to Bceniack Furnace Company, Cicero, 111., a

Corporation of Illinois a r Original application September "10, 1928, Serial Serial No. 609,920

now Patent No. i Divided, and this application May 7, 193 2.

7 Claims. (01. 263 -50) application for Enameling furnaces, Serial No' 304,945, filed September 10, 1928,. which issued May 10, 1932 as Patent 1,857,206.

In the drawings:

Fig. 1 is a front elevation of a draft controlling apparatus at one end of a furnace; Fig. 2 is a top plan view of the same;

viewed in Fig. 2;

Fig. 4 is a detached perspective of an intake member of the draft controlling mechanism; and.

the furnace of the cold air entering at the bot-' pears to be little movement of air either into the furnace or out of it. When there is a strong draft through the building in which the furnace is situated, it has been further observed that considerably more heat will escape at one end of the furnace than the other. In order to reduce the loss of heat and attain greater regularity in the operation of the furnace, I have devised a novel draft control apparatus which may be used at either or both ends of the furnace, or in any furnace in which similar conditions obtain.

In the form shown, the apparatus includes a double suction box 10, which is secured to the furnace wall 11 adjacent the top of the two furnace openings 12 at the desired end of the furnace, and is formed with openings 13 on its lower side adapted to draw in heated air tending to escape out of the top portion of the furnace openings. The suction box 10 is connected by a pipe 14 with the intake of a blower 15, the outlet of the blower being connected by a pipe 16 having branches 1'717 connected with blower boxes 1818 each secured to the furnace wall 11 adjacent the bottom of the furnace openings. The blower boxes 18 are formed each with a draft Fig. 3 is a side elevation looking to the left as outlet inheriting across the bottom of onejof thefurnace openings 12 and are arranged to discharge, transversely of the openings and towards the inlet openings 13 of the suction box 'lQ, the heated air which has been drawn in through such suction boxes, thus maintainin'g'at the furnace openings transverse sheets or blasts of heated air which act as abarrier to. the'objectional inward and outwardcurrentslabove mentioned. v;

As shown in Fig. 1 there is a slot through the tudinal openings or passageways throughrthe'furnace. The suction box 10 is located adjacent the central support for the roof and the inlet openings 13 extend approximately from said intermediate support to said slots. ture does not interfere with the vertical members which depend through said slots from the overhead conveyors. I

It would obviously be possible to provide addi- .tional suction boxes at the outer top sides of the roof extending upwardly from each of the longi- 179 Thus the strucfurnace openings, also connected with the blower, but in practice this is sometimes found unnecessary.

I claim:

ing a heated passage provided with a constantly 9, 1. In a furnace of the class described and havopen opening, a draft control device at said opening including a pump having an intake connection arranged to draw in heated air adjacent the top of the opening and a discharge connection arranged to discharge'such air in a transverse stream upwardly from' the bottom of such opening. s

2; In a furnace of the class described and having a heated passage provided with a constant- T 1y open opening, a draft control device at said opening including a pump having its intake connected to a suction box having on its inner side air along a line at the top of the furnace opening and connected also to a discharge box having on its upper side a discharge opening extending along the bottom line of the furnace opening and arranged to discharge the air drawn in upwardly in atransverse thin stream extending towards openings and having on its under side separated openings arranged to severally draw in heated:

a suction opening arranged to draw in heated air from said furnace openings, and having its discharge connected to separate discharge boxes having each on its upper side a discharge opening extending along the bottom line of the particular furnace opening and arranged to discharge the air drawn in by said pump upwardly in a transverse thin stream extending towards the line of the suction opening thereabove.

4. In a furnace comprising side walls, a roof, and an intermediate support therefor, providing parallel heated passages each having an open end adjacent the other, and a slot through the roof extending upwardly from each of said passages, a draft control device adjacent said ends, including a suction box arranged between and at the top of said furnace openings and having separated openings therein each located between said intermediate support and the corresponding slot to draw in heated air from said furnace openings, discharge boxes each having a discharge opening extending along the bottom line of one of said furnace openings,'a blower having its intake connected to said 's'uctionbox and having its outlet'connected to said discharge boxes whereby the air drawn in'bythe bloweris directed upwardly from said discharge openings in transverse thin streams extending toward the suction openingsthereabove,

5. In a furnace comprisingsi'de wallsfa roof, and an intermediate support therefor, providing parallel heate d'passages each having an open end adjac'enttheother, and a slot through the having its intake connected to one of said boxes roof extending upwardly from each of said passages, a draft control device outside of said furnace adjacent said ends and including an upper boxarra'nged between and at the top of said furnace openings and having separated openings therein each located between said intermediate the blower and directed across said furnace openings in a thin stream.

6. Means for reducing escape of heated air from theopen'end of a furnace, comprising air circulating'inechanism having an interconnected intake and outlet arranged substantially oprpositely with reference to said open end and outside the same, for creating a current of air across the same;

7. Means for reducing escape of heated air fromthe open end-of'a furnace, comprising air circulating mechanism having an air intake mernber'disposed adjacent the top of said open end, and anoppositely positioned air outlet member connected thereto and extending along substantially the entire opposite side of said opening for directing a current of air upwardly across said open end toward said intake member.

ROBERT NIACDOUGALL.

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